Usage of biodiesel blends in traditional compression ignition engine has been well sought after. But reducing the emission from vehicles has become a daunting task for researchers. In this experimental investigation, biodiesel is extracted from crude cotton seed oil by single stage tranesterification process and this extracted biodiesel is blended with diesel via B20 and B30. The blended fuel is injected along with LPG in a dual fuel mode. 7.0 mg/cycle of cotton seed oil ethyl ester was injected with liquefied petroleum gas as pilot fuel. Its performance and emission characteristics were studied in a four stroke single cylinder vertical air cooled diesel engine. It was observed that in terms of performance there was a drop when compared to conventional fuel but there was a slight reduction in emission when LPG biodiesel blends were used as fuel.